Aberrant expression of tissue-specific proteins in the thymus: a hypothesis for the development of central tolerance.

Herein we present the case for the existence of a thymic cortical epithelial cell that possesses an unusual gene transcription. It produces tissue-specific proteins that have their usual physiological functions outside the thymus and presents them, as well as household proteins, to the differentiating thymocytes. We suggest that this specialized cell enforces tolerance to most self-proteins by causing release of a signal for programmed cell death to thymocytes that express receptors for these self-antigens.